Conventionally, reduction of carbon dioxide has been performed in toxic and exhaustible-resource-derived organic solvents. Recently, from the point of view of solving environmental and energy problems, reduction of carbon dioxide in water, which is non-toxic and low-cost, has been attempted. Reduction of hydrogen carbonate ion in water at pH 6 or above using an organometallic complex has been reported (for example, see Non-patent document 1), but no report has been made on reduction of carbon dioxide performed in water using an organometallic complex.
[Non-patent Document 1]
G. Laurenczy et al., Inorg. Chem., 2000, 39, pp. 5083-5088.
The present invention relates to a reaction of carbon dioxide in a water solvent or a mixed solvent of water and organic solvent, using an organometallic complex. If carbon dioxide (CO2), instead of hydrogen carbonate ion (HCO3—), can be directly reduced by simply controlling the pH of water or a water-containing solvent, reaction can be easily controlled. This is beneficial as a reaction that is both economical and environmentally friendly.
In other words, the present invention has as an object to realize a reducing process of carbon dioxide in water, which is non-toxic and low-cost, (under mild conditions), using an organometallic complex.